Instrument for recording differentials in pressures



Feb. 20, 1923;

E. LINDBOM ET AL.

lNSTRUMENT FOR RECORDING DIFFERENTIALS IN PRESSURES.

ORIGINAL FILED JAN. 6. 1921.

FIG?

JNVVENTOQRSI 06m 12T0RNEY interior of the container may be read at any time by the attendant, and in this instrument the gas accumulating in the upper p01 tion of the container, and generated from the acid liquor, flows into the receiving box or" the instrument, and in this box it immediately, and together with the gly ccrine, causes the expansion o1 the Bourdon tube 16, with the result that this tube partially uncoils and draws the recording pin 20 partially across'the chart 21, as shown by the line 22, but the rise of the temperature, due to the ingress of the steam, results in a second pressure, indicated by the heating otthe water-tilled thermometer hulh 15. The stea i generated by the heating or this rater fi vs through the steam pipe let into the @shaped Bourdon tube, which it eitpends, and the expansion of said tube tends towarc straightening out, whichdraws on the lever 12, and turns the shaft. This action will inunediately change the direction of travel of the pin 20 on the chart 21, result being a line as indicated by the numeral 2?), as of course the chart is travelling continuously during the operation of the instruinent.

This chart is shown as a ribbon form of chart, hut it is more than likely that a circular chart will he used in place thereof. 'll'hc diii'erential is found by drawing an imaginary line from the beginning of the chart line .22 to the end of the chart line 23, and from this vase line measurements may he made to the line 23, and this will give the differential in the pressu What I claim is:

1. In an instrument for recording ditli-rentials in pressures, a container having two sources of fluid pressures, a curved tubular member communicating with said container and adaptrd to uncoil coincidently with the increase of pressure, a pen supi iane? ported ti-011i an end of said tubular meniher, a second tubular member adapted to uncoil, and coinr nicating with said container, and ope: ively connected with said pen to change its direction, and achart hlanl; under said pen.

In an instrument for recording ditii rentials in pressures, a pulp digester having a gas outlet, a travelling chart, a pen in contact h said chart, a bracket supporting said pen, a coiled tubular member secured at one end to said bracket and adapted to uneoil coincidently with pressure from sn l d w te, a hollow rotatable shaft 3 1 2i nanny member i. dig ster, tubular coil spring connected to said shart, and a bulb end steam pipe having a aerating adapted to hr insert 7, i V the 1'.

-1. in ins for recording dit- "e sur s, a pulp digester haw travelling chart, a pen 'l chart, a hraclret supativel connected to said if pring thermom: ter hulh connected with said steam 7 ed in said digest e ontreal, Quebec, Canada, this eceinher, 1.920; 

